[1] Univ Calif San Francisco, Epidemiol & Prevent Intervent Ctr, San Francisco Gen Hosp, Div Infect Dis, San Francisco, CA 94143 USA
[2] San Francisco Gen Hosp, AIDS Program, San Francisco, CA 94110 USA
[3] Univ Calif San Francisco, Dept Med, Div Infect Dis, San Francisco, CA 94143 USA
[4] Calif Dept Hlth Serv, STD Control Branch, San Francisco, CA USA